My grandma has become obsessed with coloring those adult coloring books since she was diagnosed with dementia. It has been great to keep her entertained on the days she is not at her memory care center. However, she has recently started chewing on the pencils, the writing side, in an effort to sharpen them. I have two sharpeners on the table in front of her and she still keeps biting. I'm worried it could hurt her gums or teeth or something. How do I get her to stop doing this without sitting with her at the table all day?